Starter switch



May 26 1942 c. cHlRELsTElN 2,283,972

STARTER SWITCH Filed Aug.` 9, 1941 Tf ALUM/NUM /92 '207.

BAR/UM 457 INVENTOR.

atented ay 26, i342l 1 Claim.

The invention here disclosed relates to starter switches for gaseous' discharge devices.

Special objects of the invention are to make it possible to use a greater amount of getter medium and thus to obtain higher effectiveness, through a longer period of use.

It has been found that the amount of getter which can be used is more or less critical and limited in value. Also, that vif more getter could be used, the operation of the switch would be better and it would continue effective over a longer period of time.

The present invention involves the discovery that a proportion of aluminum added to the getter medium overcomes the critical limitations mentioned and enables the use of more getter material-as an actual practical example, double the amount.

Particular details of the invention are hereinifter pointed out and broadly claimed.

'Ihe drawing accompanying and forming part of the specication is illustrative of one typical embodiment of the invention. Details however may be modified and changed all within the true intent and broad scope of the invention as hereinafter deined and claimed.

Fig. 1 is a broken part sectional side elevation of a form oi starter switch incorporating features of the invention.

Fig. 2 is a sectional view taken on the line 2-2 in Fig. 1.

As shown in the figures, the switch may comprise a bowed bimetallic strip I', supported at one end on the angularly offset end 2, of an electrode 3, in position for its free end to engage the angularly offset portion t of the second electrode 5, the latter further having an extended bent arm 6, mounting the plate 7, cupped at. 3, to carry the which can be used, can be very greatly increased by using nearly or approximately half as much aluminum.

In a present preferred embodiment,v the proportions are as follows:

. Per cent Barium ,43 Magnesium 37 Aluminum 19 to 20 This proportion of aluminum enables a pill to be used of double or even three times the size previously considered possible,

The greater amount of active material thus made available provides a switch which is faster in operation, at lower temperatures and at lower voltage.

The aluminum-barium-magnesium combination is particularly effective in a neon atmosphere diluted with approximately .5% krypton.

The lateral oiset 2 serves to support the bimetal substantially centered over the end of the press and the lateral offset t of the second electrode provides a switch contact in position to be engaged by the extreme free end of the bimetal. The inwardly olset portion 6 is disposed substantially centrally over the end of the press and in general parallelism with the free arm of the bimetal. The portion 6, extending transversely ofthe press and the inward oiset Il, provides a rugged central support for the plate. The bends in the electrodes, in addition to locating the parts in the desired relations, described, add a desirable degree of stiifness and rigidity.

What is claimed is:

Ina starter switch, wherein ay bowed bimetallic switch element operates in an atmosphere of rare gases Within a sealed container, an active medium sealed within said container and including barium, magnesium and aluminum, the aluminum being present in the proportion of approximately 20% and thereby enabling the use of a high proportion of barium, the latter being present in the proportion of approximately 43% and the magnesium in the proportion of approximately 37%.

CHARLES CHIRELSTEIN. 

